It discloses the use of a class of pyrazolo[4,3-d]pyrimidine-7-one derivatives as cGMP-specific phosphodiesterase inhibitors to treat erectile dysfunction in the international application WO9428902 (CN1124926A). Then in WO0227848 (CN1325398T), it discloses another class of pyrazolo[4,3-d]pyrimidine-7-one derivatives having a potent inhibitory activity for type V of phosphodiesterase (PDE5), which can be used for the treatment of diseases relevant to PDE enzymes.
A series of compounds having inhibitory activity against PDE5 are disclosed in the international application WO2007056955, which exhibit extremely high activity and selectivity for the PDE5 enzyme in the screening test in vitro of enzyme inhibitors and in which the compound 1-methyl-5-{2-propoxy-5-[[1-methyl-1-(2-pyrrolidin-1-yl)ethyl]aminosulfonyl]phenyl}-3-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one (compound Z, in the Example 80 in WO2007056955) represented by the following formula is included:

However, the compound will significantly degrade at high temperature and in bright light, and has poor chemical stability. Therefore it is particularly important to develop a stable form of the compound Z. Moreover, the compound has disadvantage with poor water-solubility and is difficult to be dissolved, which will cause some negative impact on the pharmaceutical preparation process. On the other hand, the compound itself has a pungent odor, which also has a negative impact on the application as pharmaceutical preparations for human. Therefore, the object of the invention is to develop a form of compound Z suitable for preparing the medicine, which should have good stability, high water solubility, low hygroscopicity, no pungent odor and so on.
The physical properties of pharmaceutical compounds and salts thereof, as well as their crystals and amorphous thereof have a greater impact on the bioavailability of the drugs, the purity of the drug substance, prescription of preparations etc. So in the pharmaceutical development, it is necessary to study what kinds of salts, crystalline forms, amorphous of the compounds are best to be as a drug. That is, since the above-described physical properties depend on the characteristics of the various compounds, it is usually difficult to predict pharmaceutically acceptable salts, crystals, and amorphousness of the original substances having good properties; therefore there is a sustained need to study a variety of compounds.
Thus, one object of the invention is to provide various salts, crystals and amorphousness of compound Z. In addition, another object of the invention is to provide crystals and amorphousness of compounds (I).
Based on the deeply study on synthesis and separation of various salts and crystals of the compound Z, and researching work on the physical and chemical properties thereof, the present inventors found the forms of salts, crystals and solvate of compound Z having excellent physical properties, which can be used as raw material for medicine directly or intermediates for the manufacture of pharmaceutical raw materials, thereby completing the present invention.